ŚB 2.6.38

It is said that the transcendental name, form, quality, pastimes, paraphernalia, personality, etc., cannot possibly be perceived by the gross materialistic senses. But when the senses are purified by the process of hearing, chanting, remembering, and worshiping the lotus feet of the holy Deity, etc., the Lord reveals Himself proportionately to the advancement of the quality of devotional service (ye yathā māṁ prapadyante). One should not expect the Lord to be an order-supplying agent who must be present before us as soon as we desire to see Him. We must be ready to undergo the prescribed devotional duties, following the path shown by the predecessors in the disciplic succession from Brahmā, Nārada and similar authorities. As the senses are progressively purified by bona fide devotional service, the Lord reveals His identity according to the spiritual advancement of the devotee. But one who is not in the line of devotional service can hardly perceive Him simply by calculations and philosophical speculations. Such a hard worker can present a jugglery of words before an audience, but can never know the Supreme Personality of Godhead in His personal feature. The Lord has clearly stated in the Bhagavad-gītā that one can know Him only by devotional service. No one can know the Lord by any puffed-up material process of challenge, but the humble devotee can please the Lord by his earnest devotional activities. Thus the Lord reveals Himself proportionately before the devotee. Lord Brahmā therefore offers his respectful obeisances as a bona fide spiritual master and advises us to follow the process of śravaṇa and kīrtana. Simply by this process, or simply by hearing and chanting the glories of the activities of the Lord’s incarnation, one can certainly see within himself the identity of the Lord. We have already discussed this subject in volume one of Śrīmad-Bhāgavatam, in connection with this verse: